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The AN/ARC-5 Command Radio Set is a series of radio receivers, transmitters, and accessories used to provide two-way Morse code and AM radiotelephone communication for U.S. Navy aircraft during World War II and the years following. It was an improvement of the Navy's ARA/ATA command set. Similar units designated SCR-274-N were used in U.S. Army aircraft. The Army set is based on the Navy ARA/ATA, not the later AN/ARC-5. ==History== The AN/ARC-5 command set was used by the US Navy from the latter part of World War II into the post-war era. It was fitted in many different aircraft types for communication between aircraft, navigation, and communication back to base. Units were available that covered much of the MF, HF, and VHF spectrum. Despite the use of octal base vacuum tubes, they were compact, rugged and light weight. Many became surplus after the war and were often converted for amateur radio use. The term "ARC-5", while correctly applied to the AN/ARC-5 series, has also come to be a generic, though incorrect, term for the ARA/ATA and SCR-274-N command set units, including those designed by the Aircraft Radio Corporation in the late 1930s.〔(Entire ARC-5 )〕 The antecedent of the AN/ARC-5 system was the U.S. Navy's ARA/ATA system, initially deployed in 1940. The designations ARA and ATA are a pre-World War II Navy equipment nomenclature. The major units of the ARA are five receivers covering 0.19 to 9.1 MHz, each unit with its own dynamotor power supply. The major units of the ATA are five transmitters covering 2.1 to 9.1 MHz, using a common transmitter dynamotor/screen modulator unit. Most units were made by the Aircraft Radio Corporation (USN manufacturer's code CBY). Many units were also made by Stromberg-Carlson (USN manufacturer's code CCT). To equip US Army Air Corps planes, the US Army adopted in 1941 a reduced set of radios from the ARA/ATA range. Designated SCR-274-N, these Army radios were electrically almost identical to their ARA/ATA counterparts, except for receiver output and modulator sidetone audio transformer output impedance. Structurally and in appearance, they were virtually identical except for most later units being left unpainted aluminum in contrast to the black wrinkle finish of the Navy sets. The designation SCR-274-N is a pre-World War II Army equipment nomenclature. The Army never acquired the ARA 1.5 to 3.0 MHz receiver, nor the ATA 2.1 to 3.0 MHz transmitter. Initially, it did not acquire the 3.0 to 4.0 MHz transmitter, nor the 0.52 to 1.5 MHz receiver, but the need to communicate on the common civil airfield frequency of 3.105 MHz plus the anticipated USAAF use of the AN/ARR-1 homing adapter (see below) compelled adding these units to the SCR-274-N. Early Army units were made by Aircraft Radio Corporation, but the vast majority was made by Western Electric, plus a few by Colonial Radio and others. In late 1943, the U.S. Navy fielded an improved and more flexible set of its ARA/ATA radios under the new Joint Army-Navy (JAN) nomenclature of AN/ARC-5. Structurally and in appearance, the AN/ARC5 series is almost identical to the former units but both receivers and transmitters are somewhat different electrically. A receiver and transmitter were added that provide four-channel crystal-controlled VHF-AM operation, along with a rarely encountered set of transmitters that provide coverage of 0.5 to 2.1 MHz. The main units of both the Navy and the Army systems were usually installed in three-receiver racks and two-transmitter racks. Units not in service could be stored on board the aircraft, just as one would store tuning units of other types of radio equipment. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「AN/ARC-5」の詳細全文を読む スポンサード リンク
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